A Computer Simulation of Blood Flow in Arterial Networks, Including Blood Non-Newtonian Models and Arterial Stenosis

The goals of this research are: 1. To construct a software that can determine pressure and flow at different points of an arbitrary arterial network; 2. To investigate the effect of non-Newtonian model on pressure and flow waves in comparison with Newtonian model. The main assumptions in our physical model are: 1- Blood flow is one dimensional and in axial direction; 2- Arteries are elastic cylindrical tubes; 3-Blood flow is laminar. The method of analysis is finite element technique. Three element types have been used: 1- Artery element for an unobstructed healthy artery, 2- Branch element for three or more artery element connections and 3- Stenosis element for an artery stenosis. Arterioles and capillary beds at the ends of arteries have been electrically modeled as a "developed Windkessel model" that includes a capacitance and a resistance in series and a resistance parallel with them. The numerical solvers were written in C++ computer language. Results of a model of femoral artery show that: a) In the points more distal to the inlet: 1) The mean pressure decreases; 2) The pressure wave peak increases; 3) Flow wave peak decreases; 4) The mean flow decreases; 5) Pressure and flow waves appear with negative phase shift in comparison with proximal ones; b) in comparison with a healthy artery, in a stenosed artery, the pressure and flow decrease, also it is indicated that in a more severe stenosis the reduction appeared to be more; c) The power law model of blood could not produce acceptable results while the Casson model produced results that are similar to the Newtonian one which agrees with the fact that in large arteries blood can be considered as a Newtonian fluid. In general the result indicates that our constructed software is reliable